I belong to a very large neighborhood yahoo listserv and people are always selling used items for cheap or even giving stuff away. I both give and receive this way. I have gotten for free furniture, a stroller, baby items, clothes, etc and I have given away exercise equipment, clothes, shoes, DVDs, etc. I like it better than Craigslist because all of the items are located closeby and I know most of the people on the listserv so no creep factor. I also rarely buy my children new clothes now. I receive hand me downs from several friends and I use Tide detergent which gets out stains easier IMO so I can make clothes last longer. I then turn around and offer my kids hand me downs to other friends. I think key is playing it forward, if someone knows I am more likely to appreciate the clothes and also keep chain of giving going, I feel I am more likely to get the hand me down. there has been a resurgence of upscale thrift stores for kids and adults and I buy most of my clothes and them, I rarely buy anything new, rarely.
I use Pinterest for ideas for my kid's birthday parties and have started doing them at home as opposed to like Gymboree. I limit my kids to one activity a week, so they can do ballet or soccer or tae Kwon do, not all of them.